What Cheer,
I missed your response the other night. The other Ross King rifle with the roller is a 30-06 that was in Michaels possession and was more of a sporting rifle than a target rifle. I don't believe that it had DST but just the roller on the issue trigger. I do think that the 06 had the same bolt checkering as this 22 but I will have to go back and try to find that info.
Is your similar rifle a 22 or 06?
Dan